Safety panel box



H. F. KRANTZ.

`SAFETY PANEL BOX.

APPLmAIIoN F1150 11116.23. 1918.

Patented Sept. 12, 1922.

3 SHEETS-SHEET 1.

H. F. KRANTZ.

SAFETY PANEL BOX.

APPLICATION FILED Auazs. 1918.

PatentedSept. 12, 1922.

3 SHEETS-SHEET 2.

H. F. KRANTZ.

SAFETY PANEL BOX.

APPLlcAloN man AuG.23,11918,

Patented Sept. 12, 1922.

3 SHEETS--SHEET 3.

A w h Patented Sept, l2, 1922.

` UNITED STATES PATENT OFFICE.

HUBERT F. KRANTZ, OF BROOKLYN,'NEW YORK, ASSIGNOR TO KRANTZ MANUFACTUR-ING COMPANY, INC., OF BROOKLYN, NEW YORK, A CORPORATION OF NEW YORK.

SAFETY PANEL BOX.

Application -led August 23, 1918. Serial' No. 251,079.

To all whom it may concern:

Be it known that I, HUBERT F. KRANTZ, residing at Brooklyn, in thecounty of Kings and State of New York, have invented certain new anduseful Improvements in Safety Panel Boxes, of which the following is aspecification.

This invention relates to a safety panel box which is in manyrespectssimilar to that shown and described in my pending application Serial No.248,330, filed August 5, 191s.

A particular object of the present invention is to provide improved andpositively operating means for rendering the panel box safe to behandled even by an inexperienced operator.

A further object is to rovide a panel box in which switch mechanism ismounted, and in which an entrance door is so associated with the switchmechanism as to preclude possibility of the switch being on after theentrance door has been opened.

A further and more detailed object is to provide a panel box havingquick break toggle operated switch mechanism therein, and to provide theentrance door for the panel box with a part disposed to positivelyengage one of the toggle members to trip the same whenever the door isopened.

Other objects and aims of the invention, more or less specific thanthose referred to above, will be in part obvious and in part pointed outin the course ot the following description of the elements.combinations, arrangements of parts and applications ot' principles,constituting the invention; and the scope of-protection contemplatedwill be indicated inthe appended claims.

In the accompanying drawings which are to be taken as a part of thisspecification, and in which I have shown merely a preferred form'or1embodiment of the invention:

Fig. 1 is a transversevertical sectional view through a safety panel boxconstructed in accordance with this invention, parts being illustratedin full lines.

Fig. 2 is a topplan view of the panel box shown in Fig. '1, and

Fig. 3 is a diagrammatic view showing the elements of Fig. 1 in twodifferent positions.

Referring to the drawings for describing in detail the structureillustrated therein the reference character L indicates the panel boxgenerally. This may be made up of any suitable material, either sheetmetal or otherwlse, according to preference. In the drawing it is shownto be made of sheet metal.

The switch mechanism within the box is represented generally by thereference character Gr. It is similar in all respects to the switchmechanism shown and. described in the above mentioned application, andincludes a switch blade carrier 1 which extends transversely across thebox and has pivot extensions 2 by which the carrier is supported insuitable bearings at opposite sides of the box.

The carrier itself is of the general construction shown and described inmy Patent 1,248,415, and includes a pair of clamp plates 3 between whichthe switch blades 4 are rigidly held in insulated spaced relation,seetions of insulating material, as 5, being interposed between theblades and the clamp plates for insulating the blades from each otherand from the clamp plates.

The blades are held by their mid-pon' tions and the opposite ends ofboth of the blades project laterally from the carrier into cooperativerelation with fixed caontacts 6-6 and 7-7 respectively, the contacts 6being the main line contacts and the contacts 7 being for branch lineconnections.

One or more'springs, as 8, are connected with the carrier to normallyurge it into position with the switch blades oft An operating handle His provided for manually moving the switch blades at will. This handleis pivotally mounted upon a pivot pin 9 which is carried. by asupporting bracket or frame 10 within the casing, the outer end of thehandle projecting through an opening 11 in the front wall or cover plate12 of the box to a position of accessibility exteriorly of the box.

A toggle, made Vup of links 13 and 14, is connected to be operated bythe handle for moving the carrier in response to the movements of thehandle. The link 13 is pivotally mounted upon the pivot pin 9 and is'connected to the link 14 by a pivot pin 15 forming the knee of thetoggle. The opposite end of the link 14 is pivotally connected, as at16, to the carrier 1 at one side of the center line of the carrier.

- Whenever the toggle is made, the blades stand on, but as soon as thetoggle is broken, the blades snap quickly into off position under theimpulse of the springs 8.

The link 13 is provided with an extensionv1 17 which is arranged toengage against the inner end of a set screw 19 carried by the coverplate 12 for limiting movement of the toggle in the made direction.Preferably this same link is also provided with anextension 20f'dispo'sed for `engaging against the inner surface of the cover plate12 to limit movement of the toggle in the broken direction.

A light spring 21 is mounted upon the pivot pin 9 adapted to engagebetween the operating handle and the frame 10 for counter-acting theweight of the outer end of the operating handle.

The operating handle 1s provided with a shoulder 22 disposed to engageagalnst a surface portion 23 of the link 13 whenever the handle is moveddownwardly to break the toggle, said shoulder being positloned to pressagainst the surface 23 onlywhen the handle is in a position near itslowest extreme of movement, the engagement being maintained onlysufliciently long to cause the pivot 15 to pass center. The springs 8then complete the toggle movement to full off position.

'Ille set screw 19 is adjustable so as to alter the degree of movementof the pivot 15 beyond center when the toggle is being made.-

he entrance door is indlcated by the reference character A and ismounted to displace a portion of the front wall 12, being pivotallymounted to swing about a hinge 24 which is preferably, though notnecessarily, disposed with its axis parallel with the axis of th'e pivot9. A sui-table latch member 25 is provided at the free edge of the doorfor engaging the adjacent portion of the box to maintain the door closedwhen desired, said Ymember also constituting a handle grip by whichconveniently to open the door.

When the door is open, access is given into the interior of the box forthe replacement of fuses, or for other appropriate purposes.

In order that the door may not be opened, however, while the fuses orother parts accessible through the door opening, are live, the. door isprovided with a heel piece 26 projecting beyond the hinge 24 adapted toengage against the extension 17 of the toggle link 13 to break thetoggle upon opening movement of the door. The heel piece 26 operatesthrough an opening 27 formed in the adjacent portion of the. cover plate12. A slight opening movement of the door, as shown by the full lines inFig. 3, will move the pivot 15 backwardly well past center and thesprings 8 will complete the olf movement and place the switch blades inthe full ol' position, as shown by the dotted lines in Fig. 3. Theblades being then of, the opening movement of the door may be continuedand the operator may insert his hand into the box without danger ofcoming into contact with any live parts. The heel 26 is formed with asubstantially concentric surface portion 28 which stands to be engagedby the extension 17 and to thereby prevent return of the switch bladeson at any time while the door is open, this 'regardless of the extent towhich the door has been swung in the opening movement.

When the toggle moves into. the off position after being engaged by theheel 26, the operating handle simultaneously moves downwardly due to theengagement of a shoulder, as 29, at the inner end of the operatinghandle with an opposing shoulder 30 carried by the link 13.

When the door is closed and it is desired to return the switch blades oman upward movement of the handle, operating through the opposingshoulders 29 and 30, restores the toggle to its straightened condition.

The shoulder 30 on'the toggle link 13 is shown as comprising the nose ofa pawl 31 which is pivotally mounted upon the extension 17 and which isadapted to cooperate with a bell-crank lever 32 for rendering the toggleoperable by an over-load control device of the kind fully shown anddescribed in the above mentioned pending application. The over-loadcontrol device is illustrated herein generally by the referencecharacter N. Briefly it comprises an over-load coil 33 which isinterposed in the branch line circuit including one of the contacts 7. Acore 34 is provided within the coil, and a movable armature 35 isarranged adjacent to the end of the core adapted to be attracted therebyand to operate the bell-crank lever 32 whenever an excess of current ispresent in the coil. A spring 36 is provided normally to cause thebell-crank lever to hold the pawl in position beneath the shoulder 29 ofthe operating handle, but when the armature 35 operates it causes thepawl to fall away from the shoulder 29 and inimediately thereafter.causes the toggle to become broken so that the springs 8 are able vtosnap the switch blades oit It will be understood from the above that inthe structure described there is present three distinct andindependently operable means for causing an olf movement of the switchblades. The rst is the operating handle. This may be moved to break thetoggle at any time irrespective of the presence of the. other two means.The second is the heel 26 on the door. This also is operable to breakthe toggle at any time regardless of the Vpresence of the other twomeans. And the third is the over-load control which is also operable atany time to break the toggle irrespective of the presence of theoperating handle or the .heel 26.

As many changes could be made in this construction without departingfrom the scope of the invention as defined in the following claims, itis intended that all matter contained in the above, description or shownin the accompanying drawings, shall be in-` terpreted as illustrativeonly and not in a limiting sense.

Having thus described my invention, what I claim as new. and desire tosecure by Letters Patent is 1. A panel box having a movable door, aswitch mechanism movable into on and olf positions, the switch mechanismincluding toggle links movable into made and broken positions, and thedoor having a part adapted when the door is opened to directly enga eone of the toggle links to operate the togg e.

2. A panel box having a movable door, a switch mechanism having a switchblade movable into on and olf positions, the switch mechanism includingtoggle links adaptedto stand in a straightened condition when the switchblade is on and to permit movement of the switch blade off when thetoggle is broken, and the door having a part operable when the door isopened to directly engage one of the toggle links to break the toggle. 4

3. A panel box having a movable door, a switch mechanism having a switchblade movable into on and off positions, the switch mechanism includingtoggle links adapted to stand in a straightened condition when theswitch blade is on and to permit movement of the switch blade off whenthe toggle is broken, the door being pivotally connected and having aheel'piece projecting beyond the pivot adapted when the door is openedto directly engage one of the toggle links to break the toggle.

4. A panel b'ox having a movable door, a switch mechanism within the boxhaving a swit-ch blade movable into on and off positions, the switchmechanism including toggle-links ada ted to stand in a straightenedcondition w en the switch blade is on and to permit movement of theswitch blade olf 'when the toggle is broken, an operating handle or theswitch mechanism disposed to project through an opening formed in thewall of the box, and auxiliary operating means for the switch mechanismcomprising a part carried by the door and operable when the door isopened to directly en'- gage one of the toggle links to thereby breakthe toggle.

5. A safety switch mechanism comprising a casing havin an entrance doorthereto, a switch blade within the casing movable into on and offpositions, a toggle comprising links movable int-o made and brokenpositions for moving the switch blade, the door being pivotally mountedand having a heel projecting beyond the pivot thereof, and one of thetoggle links having a rigid extension projecting into the path ofmovement of and directly engaging said heel whereby to break the toggleupon opening movement of the door.

6. -A safety switch mechanism comprising a casing having an entrancedoor thereto, a switch blade Within the casing movable into on and offpositions, a toggle comprising links movable into made and brokenpositions for moving the switch blade, the door being movably mounted tomove into open and closed positions, and one of the toggle links havinga rigid extension projecting therefrom into the path of movement of thedoor whereby to break the toggle upon opening movement of the door.

7. A safety switch mechanism comprising a casing having an entrance doorthereto, a switch blade wlthin the casing movable into on and offpositions, a toggle comprising links movable into made and brokenpositions for moving the switch blade, the door being movably mounted tomove into open and closed positions, one of the toggle links having arigid extension projecting therefrom into the path of movement of a partof the door` whereby to break the toggle upon opening movement of thedoor, and said mentioned part of the door being adapted to stand at alltimes while the door is open in the path of said rigid extension m uthereby to prevent ret-urn of the toggle to made position.

In testimony whereof l aiix my signature in the presence of twoWitnesses.

HUBERT F. KRANTZ. Witnesses:

GEO. W. EoKnRsoN, J, A. NEWTON.

